diff --git a/build.gradle b/build.gradle
index c5dddfc9..0833b109 100644
--- a/build.gradle
+++ b/build.gradle
@@ -9,7 +9,6 @@ plugins {
 apply plugin:'java'
 apply plugin:'maven'
 apply plugin:'maven-publish'
-apply plugin:'signing'
 
 repositories {
     jcenter()
@@ -88,6 +87,7 @@ uploadArchives {
 }
 
 if (project.hasProperty("signing.keyId")) {
+    apply plugin: 'signing'
     signing {
         sign configurations.archives
     }
diff --git a/src/main/java/org/arkecosystem/crypto/transactions/Transaction.java b/src/main/java/org/arkecosystem/crypto/transactions/Transaction.java
index 4794ba74..8252062d 100644
--- a/src/main/java/org/arkecosystem/crypto/transactions/Transaction.java
+++ b/src/main/java/org/arkecosystem/crypto/transactions/Transaction.java
@@ -12,6 +12,7 @@
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 
 public class Transaction {
@@ -31,6 +32,7 @@ public class Transaction {
     public String signature;
     public String signSignature;
     public String vendorField;
+
     public String vendorFieldHex;
 
     public static Transaction deserialize(String serialized) {
@@ -212,10 +214,52 @@ public String serialize() {
     }
 
     public String toJson() {
+
+        HashMap<String, Object> map = new HashMap<String, Object>();
+        map.put("network", this.network);
+        map.put("id", this.id);
+        map.put("timestamp", this.timestamp);
+        map.put("expiration", this.expiration);
+        map.put("type", this.type);
+        map.put("amount", this.amount);
+        map.put("fee", this.fee);
+        map.put("recipientId", this.recipientId);
+        map.put("signature", this.signature);
+        map.put("senderPublicKey", this.senderPublicKey);
+
+        if (this.vendorField != null && !this.vendorField.isEmpty()) {
+            map.put("vendorField", this.vendorField);
+        }
+
+        if (this.signSignature!= null && !this.signSignature.isEmpty()) {
+            map.put("signSignature", this.signSignature);
+        }
+
+        HashMap<String, Object> asset = new HashMap();
+        if (this.type == Types.SECOND_SIGNATURE_REGISTRATION) {
+            HashMap<String, String> publicKey = new HashMap();
+            publicKey.put("publicKey", this.asset.signature.publicKey);
+            asset.put("signature", publicKey);
+        } else if (this.type == Types.VOTE) {
+            asset.put("votes", this.asset.votes);
+        } else if (this.type == Types.DELEGATE_REGISTRATION) {
+            HashMap<String, String> delegate = new HashMap();
+            delegate.put("username", this.asset.delegate.username);
+            asset.put("delegate", delegate);
+        } else if (this.type == Types.MULTI_SIGNATURE_REGISTRATION) {
+            HashMap<String, Object> multisignature = new HashMap();
+            multisignature.put("min", this.asset.multisignature.min);
+            multisignature.put("lifetime", this.asset.multisignature.lifetime);
+            multisignature.put("keysgroup", this.asset.multisignature.keysgroup);
+            asset.put("multisignature", multisignature);
+        }
+
+        if (!asset.isEmpty()) {
+            map.put("asset", asset);
+        }
+
         GsonBuilder gsonBuilder = new GsonBuilder();
-        gsonBuilder.registerTypeAdapter(Types.class, new TransactionTypeDeserializer());
-        gsonBuilder.registerTypeAdapter(Types.class, new TransactionTypeSerializer());
-        return gsonBuilder.create().toJson(this);
+        return gsonBuilder.create().toJson(map);
     }
 
     private static class TransactionTypeDeserializer implements
diff --git a/src/main/java/org/arkecosystem/crypto/transactions/builder/AbstractTransaction.java b/src/main/java/org/arkecosystem/crypto/transactions/builder/AbstractTransaction.java
index 2d52a8b3..93f2abd3 100644
--- a/src/main/java/org/arkecosystem/crypto/transactions/builder/AbstractTransaction.java
+++ b/src/main/java/org/arkecosystem/crypto/transactions/builder/AbstractTransaction.java
@@ -13,6 +13,7 @@ public AbstractTransaction() {
         this.transaction.type = this.getType();
         this.transaction.fee = Fee.get(this.getType());
         this.transaction.timestamp = Slot.time();
+        this.transaction.version = 1;
     }
 
     public AbstractTransaction sign(String passphrase) {
diff --git a/src/main/java/org/arkecosystem/crypto/transactions/builder/MultiSignatureRegistration.java b/src/main/java/org/arkecosystem/crypto/transactions/builder/MultiSignatureRegistration.java
index 76af1e0c..6b280264 100644
--- a/src/main/java/org/arkecosystem/crypto/transactions/builder/MultiSignatureRegistration.java
+++ b/src/main/java/org/arkecosystem/crypto/transactions/builder/MultiSignatureRegistration.java
@@ -36,7 +36,7 @@ public MultiSignatureRegistration keysgroup(List<String> keysgroup) {
     }
 
     public Types getType() {
-        return Types.TRANSFER;
+        return Types.MULTI_SIGNATURE_REGISTRATION;
     }
 
 }
diff --git a/src/main/java/org/arkecosystem/crypto/utils/Slot.java b/src/main/java/org/arkecosystem/crypto/utils/Slot.java
index 0c22a716..da29a5a8 100644
--- a/src/main/java/org/arkecosystem/crypto/utils/Slot.java
+++ b/src/main/java/org/arkecosystem/crypto/utils/Slot.java
@@ -9,7 +9,7 @@
 
 public class Slot {
     public static int time() {
-        return (int) (new Date().getTime() - epoch()) / 1000;
+        return (int)((new Date().getTime() - epoch()) / 1000);
     }
 
     public static long epoch() {